浅谈北京电话局N—ISDN发展的几个问题

Ｎ－ＩＳＤＮ是一项具有广阔发展前景的业务。在分析了Ｎ－ＩＳＤＮ的现状后，对如何做好Ｎ－ＩＳＤＮ的业务发展工作。提出了一系列措施。     

B—ISDN和ATM与宽带通信业务

本文首先通过对宽带业务发展情况，ＡＴＭ标准，ＡＴＭ适配层的分析引出了ＡＴＭ对Ｂ－ＩＳＤＮ发展的作用及向Ｂ－ＩＳＤＮ过渡的步骤，并指出工发具ＳＭＤＳ和ＦＲ业务接口的ＡＴＭ交换机，对实现Ｎ－ＩＳＤＮ向Ｂ－ＩＳＤＮ过渡具有积极现实意义，其次介绍和分析了ＩＴＵ－Ｔ，日本ＮＴＴ及欧洲各国关于ＡＴＭ和Ｂ－ＩＳＤＮ的标准化活动，应用试验等情况。     

上海开放窄带ISDN业务

上海开放窄带ＩＳＤＮ业务上海市内电话局已于今年１月中旬向社会开放窄带综合业务数字网（Ｎ－ＩＳＤＮ），并接纳了首批用户。Ｎ－ＩＳＤＮ业务是以现有程控交换网为基础，经过技术改进开放的新通信业务。上海局开发的Ｎ－ＩＳＤＮ功能允许对普通电话线连接８个不同的终...     

宽带综合业务数字网技术

本文介绍了宽带综合业务数字网的定义和可提供的业务，探讨了实现Ｂ－ＩＳＤＮ的技术难题，文章通过对世界上一些Ｂ－ＩＳＤＮ试验情况的介绍，综述了Ｂ－ＩＳＤＮ的发展趋向。     

关于我国ISDN发展战略

本文简要地分析了国外ＩＳＤＮ市场走势，简述了国内外对ＩＳＤＮ的开发及应用情况，介绍了Ｂ－ＩＳＤＮ的基本特点与业务内容，指出了实现Ｂ－ＩＳＤＮ的关键技术，最后就我国如何开发ＩＳＤＮ提出了建议。     

天津市建设N-ISDN有关问题的探讨

介绍了窄带综合业务数字网（Ｎ－ＩＳＤＮ）的业务特点及种类，对天津市建设Ｎ－ＩＳＤＮ的必要性、Ｎ－ＩＳＤＮ的网络结构和基本配置等有关建设方案和其他一些问题进行了初步的探讨。     

向宽带综合业务数字网进军

本文介绍了通信发展的状况和Ｂ－ＩＳＤＮ的特性，重点提出了现有局域网Ｎ－ＩＳＤＮ网络与Ｂ－ＩＳＤＮ网络互连的策略，以及面向２１世纪宽带通信网的网络结构。最后简述了通信业务物发展趋势及利用ＡＴＭ／Ｂ－ＩＳＤＮ技术改造中国现有通信网的设想。     

宽带综合业务数字网

宽带综合业务数字网可支持任意速率的，提供以话音、数据到视频业务的综合业务数字网（ＩＳＤＮ），简称宽带综合业务数字网Ｂ－ＩＳＤＮ（ＢｒｏａｄｂａｎｄＩｎｔｅｇｒａｔｅｄＳｅｒｖｉｃｅｓＤｉｇｉｔａｌＮｅｔｗｏｒｋ），它是在ＩＳＤＮ基础上发展起来的。Ｂ－...     

窄带综合业务数字网（N—ISDN）业务介绍及有关我省建设问题的考虑

介绍了窄带综合业务数字网（Ｎ－ＩＳＤＮ）提供的业务种类，提出湖北省建设ＩＳＤＮ条件已基本具备，并分析了如何以现有的扩大本地电话网为范围组建ＩＳＤＮ。     

综合业务数字网技术讲座

综合业务数字网技术讲座赵慧玲（邮电部电信传输研究所）第五章ＩＳＤＮ设备ＩＳＤＮ设备指ＩＳＤＮ网为用户提供ＩＳ－ＤＮ业务所需要的各类设备，包括ＩＳＤＮ交换机、ＩＳＤＮ用户交换机、网络终端。接入单元和各类ＩＳＤＮ终端及终端适配器。５］ＩＳＤＮ交换机ＩＳＤ...     

ISDN在电视会议和因特网中的应用

本文介绍ISDN的基本概念 ,中国ISDN业务飞速发展的状况。并结合实际 ,着重讨论了ISDN与电视会议系统、ISDN与Internet的接入等当今ISDN应用最广泛的业务。     

N-ISDN的建设和业务开放(下)

介绍了综合业务数字网 (ISDN)及我国窄带综合业务数字网 (N - ISDN )的建设、组网及业务发展情况 ,对比了七号信令 TU P(电话用户部分 )与 ISU P(综合业务用户部分 )的差异和发展窄带综合业务数字网面临的问题     

CCITT Recommendations--Network Aspects of the ISDN

This paper presents an outline of the key network standards issues addressed in CCITT as a necessary part of the development and implementation of ISDN. The results achieved in the 1981-1984 Study Period focused on ISDN network functional requirements, ISDN numbering plan, connection types to link ISDN interfaces across the network, and the relationship of the ISDN protocol model with the seven-layer ISO model. The additional network issues which must be resolved in the current (1985-1988) Study Period are identified and briefly discussed. Of particular interest are internetworking between ISDN and existing networks, numbering plan interworking, routing, and maintenance standards. The market success of ISDN depends upon early resolution of these network standards to meet the field trials scheduled for 1986-1988 and the first implementations expected in 1988-1990.     

ATM：又一个N—ISDN？

本文简要介绍了ＡＴＭ目前的应用，ＡＴＭ的竞争对手以及影响ＡＴＭ成功的因素。最后指出目前ＡＴＭ最大的优势在于组建一个多业务网络，ＡＴＭ不会重蹈Ｎ－ＩＳＤＮ的覆辙，但也面临各种挑战。     

上海N－ISDN商用化试验网

本文主要介绍上海Ｎ－ＩＳＤＮ商用化试验网的组网方案及目前ＩＳＤＮ网所具有的业务能力，并根据测试中发现的问题和ＩＳＤＮ用户需求提出了上海地区发展ＩＳＤＮ的设想和建议。同时本文穿插介绍了几种ＩＳＤＮ终端产品，以使人们能对这些终端的功能有所了解。     

Interworking IEEE 802/FDDI LANs via the ISDN frame relay bearerservice

The author presents a generic architecture for interconnecting LANs (local area networks) through the ISDN (integrated services digital network) bearer services, particularly the frame relay bearer service. The architecture is derived from the IEEE 802.1 MAC (medium access control) bridge and ISDN frame relay standards. An algorithm for MAC/ISDN address resolution that makes minimal use of the WAN (wide area network) bandwidth (which is potentially the most expensive resource) is presented. The algorithm uses a MAC/ISDN address resolution server to resolve addresses for new stations, the resolution in all other cases (e.g. stations moving from the ISDN address to another) being fully distributed. To prevent a server failure from inhibiting communication to new stations, a backup server may be provided. A practical implementation of the architecture has been found capable of supporting full throughput at ISDN hyperchannel rates (384-1920 kb/s) for all IEEE 802.3 frame lengths. Frame relay is seen as having a number of important advantages for LAN interconnection, including the following: a large number of virtual circuits available, giving the potential for a rich interconnection architecture with single-hop connections across the ISDN; and low processing overhead enabling efficient use of ISDN channels, including ISDN hyperchannels (384-1920 kb/s)     

Implementing ISDN in the United States

Planning for implementation of ISDN is proceeding at a rapid rate throughout the United States. Planning for nationwide deployment of common-channel signaling to support database access, as well as internode signaling for ISDN is also underway. This paper describes planning for trials and initial applications of ISDN and common-channel signaling for service starting in late 1986 through early 1988, as well as ISDN demonstrations, some already in operation. In addition, this paper discusses the network and regulatory environment for ISDN implementation in the United States, standards for the U.S. environment, and trials of transition services.     

ISDN in North America

The North American ISDN Users' Forum (NIUF), intended to bring together the communities involved in shaping a market-driven competitive ISDN, is discussed. These communities include users, service providers, network equipment manufacturers, customer premises-equipment (CPE) manufacturers, and applications software developers. The role of the NIUF in the product development cycle, NIUF activities, and other important ISDN activities that complement the NIUF work are described. The beginning deployment of a national ISDN and a major demonstration of ISDN capability within North America are also discussed. It is argued that the budding cooperation between the NIUF, the standards bodies, the Corporation for Open Systems (COSs), and Bellcore suggests that migration toward a single set of well-defined specifications is underway     

Application profile for ISDN

The authors examine some key data processing applications to be used in conjunction with the voice and facsimile services as a platform for deploying ISDN (integrated services digital network) in North America. Special emphasis is placed on the emerging standards of both Accredited Standards Committees (ACS) T1 and X3 in an attempt to harmonize the computer and telecommunication industries towards providing the user with an integrated platform that is vendor-transparent and ubiquitous. This generic platform, which spans a large spectrum of businesses, is presented as a base context for defining user-specific needs and incubating the applications that directly relate to businesses. Distributed transaction processing, electronic data interchange, information retrieval, electronic mail, and file transfer together with seven supplementary services for voice and G4 facsimile are proposed for ISDN deployment in the marketplace. The authors describe how the relevant standards may be exercised through the various ISDN channels and emphasize the value of the North American ISDN User's Forum for commercializing this platform     

Software Protocol for Handling ISDN in the Packet-Switched Network

The Integrated Services Digital Network (ISDN) provides basic architecture for existing, as well as future residential plus business communications. ISDN overlayed with CCS#7 of a digital PSTN (Public Switched Telephone Network) can be the ultimate, ubiquitous network for circuit switch (voice, data), packet switch (voice, data), and private line (voice, data) applications. Assuming that the present ISDN has to interwork in the present physically separate overlayed networks (voice and data), significant problems are expected to emerge for designing hardware and linking softwares for handling packet traffic. In this paper, the software-related problems, when ISDN packet distribution nodes have to handle an ISDN interface, will be outlined with an ISDN software protocol solution. An approximation of the delay involved in the telephone switching system which is part of ISDN processing as well as the delay for the interface gateways, the HOST computer nodes, and the LAN and WAN computer nodes will be identified and formulated to reflect the total performance measure defined. Major emphasis is given to flow and congestion control performance measures in the ISDN Gateways, which are analyzed and simulated with the assistance of the basic delay table transfer software model developed for the IMPS and gateways in the ARPANET, MILNET, and MINET. The performance evaluation of this basic ISDN interfacing software, which only involved one ISDN level, i.e., the HOST or gateway and its related subnetworks, is simulated on sections of these networks to illustrate its congestion control effectiveness. There are six mathematical software techniques to account for end-to-end delay, which form the basis for the solution to these ISDN software-hardware problems in the Interface Gateways connecting the electronic switch to the computer network components.